$file1 = "probesets_A";
$file2 = "probesets_B";
open(BUFF1,$file1);
open(BUFF2,$file2);
open(WRBUFF,">probesets_only_B");
while($line = <BUFF1>)
{
	chomp($line);
	$hash{$line} = "k";
}
while($line = <BUFF2>)
{
        chomp($line);
	if(exists($hash{$line}))
	{
	
	}
	else
	{
		print WRBUFF $line."\n";
	}
}
